Method of forming composite floor construction.



R. H. ROBINSON. METHODiOF FORMING COMPOSITE FLOOR CONSTRUCTION. APPLICATION FILED JULY 29. 1908.

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ROY H. MROBINSON, OFCHICAGO, ILLINOIS.

IYIETHOD OF FORMING CUMPOSITE FLOOR CONS/TRUGTION.

To all whom t may concern Be it known that I, ROY I-I. ROBINSON,

fa citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and Improved Method of Forming Composite Floor Construction, ofV which the following is aspecilication.'l i 4 This invention relates to a new and 1mproved composite Hoor construction and -method of forming the same, andrelates strength and minimum amount of material,

the elements of the structure being so disposed as to best utilize the full eiiciency of each of the several components; to provide a method of construction and a construction which may be readily modified -to afford more or less strengthin accordance withthe requirements of given cases, without departingy from the spirit of the invention; to provide a ,construction which may be erected with great expedition and without the employment of special skilled labor; and in general to provide improvements inthis art.

The invention consists in the matters hereinafter described, and more particularly pointed out in the appended claims.

In thev accompanying drawing- Figure l is a transverse vertical sectional view of afloor construction embodying one form of my invention, the lower half or vstrata of the construction being largely formed ofV tiles; Fig. 2 is a perspective view of one of the tiles employed in the construction shown in Fig. 1 Fig. 3 is a modification in which the tiles are dispensed with and arch-shaped hollows formed in the stead of the tiles; Fig.

4 is a fragmentary perspective view ofthe skeleton frame form/ed of the metallic reinforcements of the construction shown 'in Fig. 3; Fig. 5 is a fragmentary perspective view of one of the joist nuclei or reinforcements provided with a reinforcing coating of concrete as to its lower portions.

In every floor structure which has to sup- `Specication of Letters Patent.

- rat-@atea May ie, raie.

Application led July 29, 1908. Serial No. 446,016.

port any considerable weight 'there are, of

course, two classes of stresses, viz: tension stresses in the lower half of the structure and compression stresses in the upper half. Concrete is admirably suited to resist compression stresses but is weak in tensile strength. It is not unusual to supplement the tensile strength of the concretein a composite floor structure of this character by metal reinforcements. However, in the present invention I not only supplement the concrete by metallic -reinforcements but I utilize reinforcements of such character and adopt such a method of'procedure in making the ioor that these metallic reinforcements become the nuclei of joists or supporting beams which are made strong enough to support the entire addeds mass of concrete which forms the greater 'part of the weight of the floor while the chief mass of concrete is plastic and incapableof supporting itself. Moreover, I so organize the structure and proceed in such manner that 'in the finished structure the metallic reinforcements are as effectually embedded in, and .mechanically bonded'with, the mass of concrete as though molds had been provided' and the concrete poured into these molds and around the reinforcements, and in organizing the structure due regard is had to so positioning the metallic reinforcements that they will occupy most eiiicient locations andarrangement in the structure.

Describing generally my method of procedure, I rst erect a series or set of web or sheet-like metal reinforcements as joist nuclei.; arranging these webs vertically in the final positions in which they are to remain in the structure, and connecting them with the cross beams or main frame of the structure in any usual or suitable Away. These joist nuclei are of such character that con ,crete will mechanically bond with both the vmain surfaces thereof and they may be formed of expanded sheet metal, perforated sheetmetal or sheet Vmetalcorrugated into inclave form. The last lmentioned form of reinforcement is preferred. With a view to economy in the use of metal, I employ for these web-like reinforcements material which is comparatively thin and of a width considerably less than the thickness of the nished floor structure; it being obvious that there is little utility in carrying these reinforcing webs much above a point midthiclmess of the ioor structure, since their function in the l`finished structure is to afford tensile reinforcement. However, inasmuch as I employthese joist nuclei tosupport the `chief mass of Aconcrete while the latter is plastic, I proceed to augment the strength of the webs by adding to them supplemental reinforcing material which also becomes a component part of the finished structure. Preferably I apply coatingsof concrete orl cementitious material toboth sides of the lower portions of thesevjoist nuclei, and perl mit this to harden, thereby producing\ a composite joist'composed of concrete with af vertical metallic reinforcing web extending economize in concrete and avoid excess weight without materially lessening the strength of the structure, I .provide either permanent or temporary centerings arranged to extend from joist to joist and then fill in the concrete around the joists and overlying the centerings so as to provide a continuous up er layer of concrete, and beam-like extensions upon the lower side of this upper layer, within whch the joists are inclosed to form a monolithic structure. The method will be more exactly understood by adescription of the manner in' which the several structures herein described are made.

Referrin to the drawing, in Fig. 1, 1,1, designate s eet metal webs of ferro-inclave form arranged with their planes vertical,

spaced at suitable intervals apart, and suit-- ably united at their ends to the 'main stringers or cross beams of the structure.

2, 2, designate concrete coatings applied to both sides of ltheI lower portions of these joist nuclei 1; the concrete coatings being in the construction shown in Fig. 1 so shaped as to provide horizontal shoulders at each side, and 'upwardly widening or thickening portions 4 above the shoulders. The concrete may be applied to` the inclave sheet, so as to produce the cross sectional form shown, by being plastered thereon by a reinforced and allowed to harden, I next arrange sets ofhollow tiles 6 in position between the joist nuclei and'interlocked with the latterin such manner as to form fiat arches. As shownin Fig. 1, each tile is made of ay length sufficient to bridge the space'from joist to joist, and is provided at its end margin with shoulders 7 which engage the shoulders 3 of the joists hereinbefore described. The end walls of each tile converge upwardly so that spaces 8 are provided between' these walls and the proximate sides of the initial concrete coatings of the joists. Having thusaarranged the tiles in position, the upper layer 9 ofl concrete is filled in and spread over the entire area, so as to .form an upper layer of considerable thickness of solid concrete and so as to fill into. thev spaces 8 between the tiles and the 'joists and thus unite monolithically with the latter. It will. be noted that when the chief mass of concrete is illedjn, the upper exposed edges of the web remforcements are alsocovered and bonded into the mass. Usually a coating of plaster 10 will be applied to the lower surface of the tiles and also edges of the joists to afford a suitable uniform ceiling finish.

In the construction shown in Fig. I dispense with the tiles. In forming thisco struction I employ 'reinforcing webs 1 which are provided in their lower edges with inverted L-shaped notches 11, 'or other suitable apertures, at suitable spaces apart, and after the web reinforcements have been erected and secured in place, I insert reinforcing bars or rods 12 in to these notches 11 so that they extend transversely( across the lower edges of the' webs and are supported bythe latter. If desired I also Sup; port a set of longitudinally disposed reinforcing bars 13' upon the set of bars-.12, and I then attach metal lathing, or some similar fabric, to the nder side of the skeleton structure thus ormed, thus providing a continuous skeleton ceiling su ciently close in mesh to retain concrete or plaster. I-next proceed'to apply a layerrof concrete 14 tothe upper .side of this skeleton ceiling, and preferably also apply coatingsof concrete to both'sides of the respective joist nuclei orl webs, as indicated in dotted lines at 15, 15, and allow these coatings of concrete to dry andharden. The structure 4 is now strong enough to support any reason-- trowel, either before or after` the web re1nforcement has been erected,'or if done before erection it may be applied in this form by passing the web through a suitable mold-Y ingmachine which applies the concrete in plastic condition. If additional metallic reinforcement is desired,I I associate reinforcing rods or bars 5 with the lower edges of the webs before the concrete is applied thereto. These j oist nuclei having been thus able weight of' material, and I 'may' fill m with concrete t0 any desired thickness betweenthe joist nuclei and above the latter but preferably before filling in the ma`ss ofY cement I arrange arch-shaped supporting sheets to extend from one joist tothe next, as indicated at 16, so as to leave the arch` shaped hollows shown in Fig. 3. Thesev sheets may be of metal, or even a reasonably thick andstiff qualityl of cardboard, since their only function is to support the concrete while plastic and until it hardens, and this in' a space which is entirely sealed in. After arranging the arched sheets as described, the main mass of concrete 17 is filled in as in the first described construction, and thereafter the under surface of the ceiling is plastered or otherwise finished.

It will be noted that in making each of the several constructions described, the method of procedure is in general the same; that each construction is characterized by the employment of web or sheet-like metallic joist nuclei which are made to serve as skeletons upon which to build up the main structure; that in each instance the metallic reinforcements are so disposedas to fbest strengthen the structure against the tensile stresses to which the lower half of the floor structure is subject, and that in each con struction the strength incidental' to the use of a deep body of concrete is secured while but little more than half of thequantity of concrete necessary to make a solid structure of equal thickness is employed. `Those parts of the structure which I have referred to as joists are, of course, in the finished structure more in the nature of integral beam eXtensions upon the under side of the main layer of concrete and are in each instance monolithic parts of said main layer. It will be obvious that other modifications may bel made Without departing from, the spirit of the invention. l

I claim as my invention:

l. The herein described method of forming composite floor constructions, which consists in first erecting in their final positions web-like attenuated metal joist nuclei, each comprising a sheet metal webr of ferroinclave form, each arranged with its plane vertical, or substantially so, then attaching and mechanically 'interbonding with oppov site sides of each joist nucleus a concrete coating and allowing the coating to harden whereby the joist is reinforced in strength and made capable of supporting its share of the full weight of the floor construction, then adjusting supporting arches to extend between the lower portions of the. contiguous joist nuclei and then adding a vfilling of plastic concrete to form an upper layer which bridges the spaces between. the joists and embeds and unites monolithically with the joist nuclei.

2. The herein described method `of form ing composite floor constructions, which consists in first erecting in their final positions web-like attenuated metal joist nuclei each having both surfaces fabricated into projections and cavities adapted to interbond with plastic concrete, each arranged withits plane vertical, or substantially sc, then ap-1 plying and mechanically interbonding with opposite sides of each joist nucleus, a concrete coating, and allowing the same to harden .whereby the joist is reinforced in strength and made capable ofsupporting its share of the full weight of the floor construction, then adjusting supporting arches to extend between the lower portions of the contiguous joist nuclei and then adding a filling of plastic concrete to form an upper layer which bridges the spaces between joists and embeds and unites monolithically with the j oist nuclei.

3. The herein described method of forms ing composite floor construction, which consists in first erecting in their final positions web-like attenuated metal joist nuclei, each comprising a metal web adapted to receive and interbond with plastic concrete, each arranged with its plane vertical, or substantially so, then attaching and mechanically interbonding with opposite sides of each jois't nucleus a concrete coating and allowing the coating to harden whereby' the joist is reinforced in strength and made capable of supporting its share of the full weight of the Hoor construction, then adjusting supporting arches to extend between the lower portions of the contiguous joist nuclei and then adding a filling of plastic concrete te form an upper layer which bridges the spaces between the joists and embeds and unites monolithically with the joist nuclei.

f ROY H. RGBINSON.

Witnesses:

L ALBERT H. GRAVES,

Lois FORGE. 

